[19a-B3-1~9] 6.2 Carbon-based thin films

10:45 AM - 11:00 AM JST(1:45 AM - 2:00 AM UTC)

[19a-B3-7] First-principles calculations on the ferromagnetism in Q-carbon

〇QIANG YUE¹, Yokoya Takayoshi¹, Muraoka Yuji¹ (1.Okayama Univ. RIIS.)

Keywords:

amorphous carbon film,Ab-initio Molecular Dynamics Study,ferromagnetism

A new carbon-based material, Q-carbon, is formed in a non-equilibrium process by laser annealing [1]. Q-carbon has a high sp³ content (75% – 85%) and is known to exhibit ferromagnetism with a saturation magnetization of 0.4 μ_B/atom at room temperature [2]. The mechanism of ferromagnetism has been calculated theoretically [3] [4] for systems with densities below 3.4 g/cm³, but no conclusion has been reached that can explain the experimental results. Recently, an experimental study has reported that the density of Q-carbon is 5.0 g/cm³ [5]. Therefore, in this study, we performed spin-constrained first-principles calculations on amorphous carbon systems with high densities (5.24, 5.46, and 5.63 g/cm³).